Abstract

There is described an industrial robot with a new configuration including an arm rotatably mounted around a first vertical axis on a fixed body, a second body rotatably mounted around a second vertical axis below said arm, a parallelogram linkage rotatably mounted around a third horizontal axis on the second body and a wrist carried by the parallelogram linkage and articulated around two mutually orthogonal axes.

Description

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"Industrial robot" The present invention relates to industrial robots, of the type comprising a plurality of elements articulated to each other around respective articulation axes and provided with a plurality of electric motors for driving ratation of each articulated element of the robot around the respective articulation axis and a reduction gear unit interposed in the connection between each electric motor and the respective driven element.~ he ob~ect of the present invention is that of providing an industrial robot of the type indicated above, which is particularly, but not exclusively, to be produced as a robot of small size for carrying out e.g. arc-welding operations or for handling relatively light articles, which has a structure very simple and constituted by a reduced number of parts and which can be assembled with easy and rapid operations. In order to achieve this object, the invention provides an industrial robot of the type indicated at the beginning, characterized in that said robot comprises a fixed support body, and arm rotatably mounted around a first vertical axis onto said fixed support body, a second body rotatably mounted around a second axis, which is also vertical, below said arm, a parallelogram linkage rotatably mounted around a third horizontal axis onto said second body and including a first element carried by the parallelogram linkage, a second element rotatably mounted on said first element around a fourth axis and a flange rotatab-le on said second element around an axis orthogonal to said fourth vertical axis. Further features and advantages of the invention will become apparent from the following description ~7n2~

with reference to the annexed drawings, given purely by way of non limiting example, in which: figures 1, 2 are a side view and a plan view of a preferred embodiment of the robot according to the invention With reference to these figures, the robot, generally designated by reference 70, comprises a fixed body 71 which rotatably supports around a vertical axis 1 an arm 10 carrying two electric motors 39, 51 with associated reduction gear units at its ends. The arm 10 rotatably supports around a vertical axis 2 a body 72 mounted below the arm 10. The two motors 39, Sl drive the rotation around axes 1, 2. Preferably, the reduction gear units associated therewith are integrated in the structure of arm 10, i.e. this structure acts directly as a casing of the gear reduction transmission, according to what is indicated in a copending application of the same applicant. The rotating body 72 rotatably supports around an axis 3 a lever 73 forming, along with a further lever 74, a parallelogram linkage 75. Lever 74 is articulated to body 72 around an axis 76 parallel to axis 3. The two levers 73, 74 are articulated at 77 and 78 to an arm carrying a wrist 80 comprising a first body 81, a second body 82 rotatably mounted below body 81 around a vertical axis 4 and a flange 83 rotatably mounted onto body 82 around an horizontal axis 5. Due to the above described structure, the robot according to the invention may reach any point in an extended area whose outline is diagrammatically indicated by A in figure 1. At the same time, the structure of the robot is simple and inexpensive. The robot is very flexible in operation and may move at very high speeds.

The rotation of the parallelogram linkage 75 around axis 3 is driven by an electric motor and reduction gear unit 7Za (figure 2), while rotations of elements 82, 83 around axes 4, 5 are controlled by electric motor and reduction gear units 80a, 80b (figure 1). The details of canstruction of the above mentioned electric motor and reduction gear units are not described herein nor shown in the annexed drawings, since such details may be of any known type and do not fall, ta~en ~ se, within the scope of the present invention. Furthermore, the elimination of these details from the drawings renders the latter more easy to understand. Naturally, while the principle of the invention re~i n.~ the same, the details of construction and the embodiments may widely vary with respect to what has been described and illustrated purely by way of example, without departing from the scope of the present invention. For example, the robot may be used with a different orientation from what has been illustrated, i.e. with its axes 1, 2, 4 inclined with respected to the vertical direction. In figure 1, the dotted line S shaws an alternative mounting position of the wrist, in which axis 4 is horizontal and axis 5 is vertical.

Claims (3)

1. An industrial robot comprising a plurality of elements (71,10, 72,81, 82) articulated to each other around respective articulation axes (1-5) and provided with a plurality of electric motors (39, 51, 72a, 80a, 80b) for driving rotation of each articulated element of the robot around the respective articulation axes (1-5) and a reduction gear unit interposed in the connection between each electric motor and the respective driven element, said robot comprising a fixed body (71), an arm (10) rotatably mounted around a first axis (1) on said fixed body (71), a second body (72) rotatably mounted around a second axis (2), which is vertical, below the arm (10), a parallelogram linkage (75) rotatably mounted around a third horizontal axis (3) on said second body (72) and a wrist (80) carried by said parallelogram linkage (75) and including a first element (81) carried by the parallelogram linkage, and a second element (82) rotatably mounted on the first element (81) around a fourth axis (4), wherein said first axis (1) of articulation of said arm (10) to said fixed body (71) is vertical, so that said arm (10) is able to move in a horizontal plane, said second body (72) is rotatably supported around said second vertical axis (2) by the structure of said arm (10), and said wrist (80) further includes a flange (83) rotatable on the second element (82) around an axis (5) orthogonal to said fourth axis (4).

2. An industrial robot comprising a plurality of elements articulated to each other around respective articulation axes with each said articulated element being provided with an electric motor for driving rotation of each said articulated element of the robot around the respective driven element, wherein said robot comprises a fixed body, an arm rotatably mounted around a first vertical axis on said fixed body, a second body disposed below said arm and rotatably mounted around a second vertical axis, a parallelogram linkage rotatably mounted around a third horizontal axis on said second body and a wrist carried by said parallelogram linkage and including a first element carried by the parallelogram linkage, a second element rotatably mounted on the first element around a fourth axis and a flange rotatable on the second element around an axis orthogonal to said fourth axis.

3. An industrial robot according to claim 2, wherein a reduction gear unit is interposed in the connection between each electric motor and its respective driven element.